From cc79cf3b3ae9741abfeb72450f9d9094c10fc53a Mon Sep 17 00:00:00 2001
From: Pedro Pombeiro <pombeirp@users.noreply.github.com>
Date: Thu, 22 Aug 2019 18:36:59 +0200
Subject: [PATCH] Enable Hermes in Android. Fixes #8952

Signed-off-by: Pedro Pombeiro <pombeirp@users.noreply.github.com>
---
 Makefile                                      |  5 ++++
 android/app/build.gradle                      | 10 ++++---
 .../android/maven-and-npm-deps/default.nix    | 26 +++++++++++++++++++
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index d1fda96aad..77253248c8 100644
--- a/Makefile
+++ b/Makefile
@@ -264,6 +264,11 @@ geth-connect: ##@other Connect to Geth on the device
 	adb forward tcp:8545 tcp:8545 && \
 	build/bin/geth attach http://localhost:8545
 
+android-clean: export TARGET_OS ?= android
+android-clean: ##@prepare Clean Gradle state
+	git clean -dxf -f ./android/app/build
+	[ -d android/.gradle ] && cd android && ./gradlew clean
+
 android-ports: export _NIX_ATTR := targets.mobile.android.adb.shell
 android-ports: export TARGET_OS ?= android
 android-ports: ##@other Add proxies to Android Device/Simulator
diff --git a/android/app/build.gradle b/android/app/build.gradle
index 720e3120fd..319bc0233c 100644
--- a/android/app/build.gradle
+++ b/android/app/build.gradle
@@ -79,7 +79,7 @@ import com.sun.org.apache.xalan.internal.xsltc.compiler.Copy
 project.ext.react = [
     nodeExecutableAndArgs: ["node", "--max-old-space-size=16384"],
     entryFile: "index.android.js",
-    enableHermes: false,  // clean and rebuild if changing
+    enableHermes: true,     // clean and rebuild if changing. NOTE: Hermes engine is required for Android 64-bit builds running on 64 devices, to guard against a hang in the UI thread after invoking status-go
     bundleInPr: true,
     inputExcludes: ["android/**", "ios/**", "react-native/**", "src/**", "test/**"]
 ]
@@ -304,9 +304,11 @@ dependencies {
 
     if (enableHermes) {
       def hermesPath = "../../node_modules/hermesvm/android/";
-      debugImplementation files(hermesPath + "hermes-debug.aar")
-      releaseImplementation files(hermesPath + "hermes-release.aar")
-      prImplementation files(hermesPath + "hermes-release.aar")
+      // Force using the release Hermes VM until the perf issues in debug VM are fixed in npm package > 0.1.1 (https://github.com/facebook/hermes/issues/73)
+      implementation files(hermesPath + "hermes-release.aar")
+    //   debugImplementation files(hermesPath + "hermes-debug.aar")
+    //   releaseImplementation files(hermesPath + "hermes-release.aar")
+    //   prImplementation files(hermesPath + "hermes-release.aar")
     } else {
       implementation jscFlavor
     }
diff --git a/nix/mobile/android/maven-and-npm-deps/default.nix b/nix/mobile/android/maven-and-npm-deps/default.nix
index ea3dbb1032..f7b01de6f1 100644
--- a/nix/mobile/android/maven-and-npm-deps/default.nix
+++ b/nix/mobile/android/maven-and-npm-deps/default.nix
@@ -73,6 +73,9 @@ let
           mkdir -p ${projectBuildDir}/node_modules
           cp -a ${projectNodePackage}/node_modules/. ${projectBuildDir}/node_modules/
 
+          # Ensure that module was correctly installed
+          [ -d ${projectBuildDir}/node_modules/jsc-android/dist ] || exit 1
+
           # Adjust permissions
           chmod -R u+w ${projectBuildDir}
 
@@ -145,6 +148,29 @@ let
               'nodeExecutableAndArgs: ["node"' \
               'nodeExecutableAndArgs: ["${nodejs}/bin/node"'
 
+          # Fix bugs in Hermes usage (https://github.com/facebook/react-native/issues/25601#issuecomment-510856047)
+          # - Make script always include release Hermes VM, as the debug version is currently way too slow in npm package <= 0.1.1 (https://github.com/facebook/hermes/issues/73)
+          # - Make PR builds also count as release builds
+          # - Fix issue where hermes command is being called with same input/output file
+          substituteInPlace ${projectBuildDir}/node_modules/react-native/react.gradle \
+            --replace \
+              'def isRelease = targetName.toLowerCase().contains("release")' \
+              'def isRelease = true' \
+            --replace \
+              'targetName.toLowerCase().contains("release")' \
+              '!targetName.toLowerCase().contains("debug")' \
+            --replace \
+              'commandLine(getHermesCommand(), "-emit-binary", "-out", jsBundleFile, jsBundleFile, *hermesFlags)' \
+              'def jsBundleFileIn = File.createTempFile("index.android",".tmp")
+              jsBundleFileIn.deleteOnExit()
+              ant.move(
+                  file: jsBundleFile,
+                  tofile: jsBundleFileIn
+              );
+              commandLine(getHermesCommand(), "-emit-binary", "-out", jsBundleFile, jsBundleFileIn, *hermesFlags)
+              ' \
+            || exit
+
           # Patch dependencies which are not yet ported to AndroidX
           npx jetify